The effect of environment on fatigue crack growth behavior of aluminum alloy 5456

A microscopic study on the corrosion fatigue of ultra-fine grained and conventional Al–Mg alloy

“…In addition to anodic dissolution, hydrogen embrittlement is a governing mechanism that can be used to describe the accelerated crack growth in the UFG alloys. Menzemer and Srivatsan [75] found hydrogen embrittlement to be the fundamental reason for accelerated crack growth in AA5456 alloys. Jones et al [76,77] have described the process of hydrogen embrittlement for AA 5083 alloys through a series of detailed steps: (1) mechanical interaction between the crack and b-phase particle whereby the crack may get trapped, (2) preferential corrosion of the b-phase which converts the particle to Al 2 O 3 , (3) hydrogen evolution occurs as a result of corrosion of the b-phase which then absorbed and diffuses ahead of crack, (4) subsequent crack propagation through or around the particle with concurrent hydrogen uptake, (5) the crack will advance towards the next particle by the hydrogen induced process, whereby it will be eventually halted by mechanical interaction, (6) the process starts all over again.…”

“…In corrosion fatigue the surface oxide layer is continually fractured due to the cycle nature of the loading. This process consistently exposes a new surface which reacts with constituents in the environment, thus creating a more intense crack growth [75,78].…”

Friction stir lap welding of 5456 aluminum alloy with different sheet thickness: process optimization and microstructure evolution

“…Because of the tool rotation the thermomechanical conditions are not similar in the advancing and retreating sides of the weld and as a result the microstructure of the material in the WN not identical on both sides of the weld and therefore different mechanical behaviors may be expected from each region in the WN. In addition to the WN, two other regions, heat affected zone (HAZ and thermomechanically affected zone (TMAZ) have also been identified as important locations in a FS weld that determine weld integrity [3,[6][7][8][9][10]. The combination of heat and deformation along the specific characteristics of each alloy (phase transformation, size and distribution of precipitates, etc.)…”

“…Microstructure, mechanical properties, and corrosion behavior of FSW butt joints of Al 5456 have been investigated [7,8]. Especially, the influence of weld process parameters on grain growth and precipitate evolution were discussed [7,8].…”

“…Especially, the influence of weld process parameters on grain growth and precipitate evolution were discussed [7,8]. Also, the effect of environment conditions (such as laboratory air, water vapor and oxygen) on fatigue crack growth of FSWed 5456-H116 alloy has been investigated [7].…”